The present invention is directed to a transponder for an aircraft and method of providing additional transponder and receiver capability to an aircraft having an existing transponder. While the invention may be used to provide a variety of capabilities, it is particularly useful in providing automatic dependent surveillance broadcast (ADS-B) capability to aircraft having only a transponder.
Aircraft operating in the United States National Airspace System (NAS) will be required to be equipped with ADS-B output (ADS-B OUT). Each such ADS-B OUT equipped aircraft will broadcast its position and other information, typically on one of two frequencies. In addition to the airborne component, a network of ground stations is being installed throughout the United States. These ground stations will receive the ADS-B broadcasts from aircraft and rebroadcast that information on the other frequency. In addition, position reports from aircraft not broadcasting ADS-B messages, but which are transponder-equipped, will be broadcast from the ADS-B ground stations as traffic information system broadcast (TISB) messages.
As a result, aircraft equipped with only a transponder, such as a Mode S extended squitter or an air traffic control radar beacon system (ATCRBS), will need to be upgraded.